Rhinosinusitis is an inflammatory disorder involving the mucosa of the nasal cavity and paranasal sinuses and represents a common reason for presentation to primary care and otorhinolaryngology services. Acute rhinosinusitis is generally characterized by sudden onset of symptoms lasting less than 12 weeks, whereas chronic rhinosinusitis is characterized by symptoms persisting for at least 12 weeks.1 Although most cases follow an uncomplicated course, bacterial infection can occasionally extend beyond the confines of the paranasal sinuses and cause orbital, intracranial, or osseous complications.1,2

Orbital complications constitute the most frequent major complications of bacterial rhinosinusitis. EPOS 2020 reports that orbital complications account for approximately 60–80% of complications of acute bacterial rhinosinusitis.1 Their clinical importance arises from the possibility of rapid progression to visual impairment, intracranial infection, cavernous sinus thrombosis, or other serious morbidity. The close anatomical relationship between the paranasal sinuses and orbit provides a pathway for contiguous spread of infection.1,3

The ethmoid sinuses are particularly important because they are separated from the orbit by the lamina papyracea, a very thin bony plate that may contain congenital or acquired dehiscences. Infection may therefore spread directly through this barrier. Additionally, the valveless venous communications between the sinus mucosa and orbital structures permit retrograde propagation of infection and septic thrombophlebitis.1,3,4 Ethmoid disease is consequently frequently associated with orbital involvement, although maxillary, frontal, and sphenoid sinus infections may also produce orbital complications.

Chandler et al. proposed the classical classification of orbital complications of sinusitis in 1970.2 It divides complications into five groups: preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess, and cavernous sinus thrombosis. Although modifications have subsequently been proposed because preseptal disease and cavernous sinus thrombosis are anatomically distinct from true orbital infection, Chandler's classification remains widely used clinically because of its simplicity.3,5

Clinical presentation varies according to the extent of infection. Eyelid edema and erythema may predominate in preseptal disease, whereas proptosis, chemosis, painful or restricted extraocular movements, diplopia, and visual deterioration raise concern for postseptal involvement.1 Visual acuity, color vision, pupillary responses and ocular motility should therefore be carefully and repeatedly assessed. Contrast-enhanced computed tomography (CT) of the paranasal sinuses and orbit plays a central role in identifying sinus disease, distinguishing cellulitis from abscess formation, and guiding surgical management.1,3

Management depends on clinical severity and radiological findings. Intravenous broad-spectrum antibiotics and close ophthalmological monitoring form the basis of treatment. Abscess formation, progressive ophthalmological signs, deterioration of vision, or failure to improve despite adequate intravenous antimicrobial treatment may warrant surgical drainage and endoscopic management of the involved sinuses.1

The present study was therefore designed to evaluate the clinical presentation, sinus distribution, severity, treatment modalities, and clinical and visual outcomes of orbital complications associated with acute and chronic rhinosinusitis.

A prospective observational study was designed to be conducted jointly by the Departments of Otorhinolaryngology and Ophthalmology at a tertiary care teaching hospital over a period of 18 months. Study Population Patients presenting to the outpatient department or emergency services with clinical features suggestive of an orbital complication secondary to acute or chronic rhinosinusitis were screened. Patients fulfilling the predefined inclusion criteria and providing informed consent were enrolled. A sample of 60 consecutive eligible patients was considered for the illustrative study dataset. Inclusion Criteria Patients of either sex and all eligible age groups with clinical evidence of rhinosinusitis accompanied by periorbital/orbital manifestations and radiological evidence supporting sinonasal origin were included. Patients with preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess, or cavernous sinus thrombosis attributable to rhinosinusitis were eligible. Exclusion Criteria Patients with orbital cellulitis caused primarily by trauma, orbital surgery, dacryocystitis, odontogenic infection without sinonasal extension, orbital tumors, isolated ocular infection, or other non-sinonasal causes were excluded. Patients with incomplete clinical or radiological evaluation were also excluded. Clinical Evaluation Detailed history was obtained regarding duration of nasal obstruction, nasal discharge, facial pain or pressure, headache, fever, previous episodes of sinusitis, allergy, diabetes mellitus, immunosuppression, previous sinonasal surgery, and prior antibiotic treatment. ENT examination included anterior rhinoscopy and diagnostic nasal endoscopy wherever clinically feasible. Nasal discharge, mucosal edema, polyps, crusting, and anatomical abnormalities were documented. Every patient underwent detailed ophthalmological evaluation. Eyelid edema and erythema, chemosis, proptosis, globe displacement, extraocular movements, diplopia, pupillary response, visual acuity, color vision where possible, intraocular pressure when appropriate, and fundus findings were recorded. Serial ophthalmological assessments were undertaken to identify progression or improvement. Classification Orbital complications were classified according to the Chandler system:2 • Stage I – Preseptal cellulitis • Stage II – Orbital cellulitis • Stage III – Subperiosteal abscess • Stage IV – Orbital abscess • Stage V – Cavernous sinus thrombosis Radiological Evaluation Contrast-enhanced CT of the paranasal sinuses and orbits was performed in patients with suspected postseptal disease, severe clinical presentation, visual symptoms, or suspected abscess. Sinuses involved, orbital fat changes, subperiosteal collection, intraorbital collection, proptosis, bony abnormalities, and possible intracranial extension were recorded. MRI was reserved for selected patients where cavernous sinus thrombosis or intracranial extension was suspected. Treatment Patients were admitted and started on appropriate intravenous broad-spectrum antimicrobial therapy according to local antimicrobial policy and subsequently modified according to microbiological culture and susceptibility results when available. Supportive measures included analgesics, nasal saline irrigation and other appropriate sinonasal therapy. Patients with uncomplicated preseptal/orbital cellulitis showing satisfactory clinical improvement were managed medically with close ENT and ophthalmological monitoring. Surgical intervention was considered in patients with abscess formation, visual deterioration, progressive proptosis or ophthalmoplegia, neurological complications, or inadequate improvement despite appropriate medical treatment. Endoscopic sinus surgery with drainage of the involved sinus and/or orbital/subperiosteal collection was performed as indicated. Outcome Assessment Outcomes assessed included resolution of orbital swelling, improvement in ocular motility, recovery of visual acuity, need for surgery, duration of hospitalization, residual visual deficit, recurrence, and mortality. Statistical Analysis Data were entered into a spreadsheet and analyzed using appropriate statistical software. Continuous variables were summarized using mean ± standard deviation or median and interquartile range according to distribution. Categorical variables were expressed as frequency and percentage. Chi-square or Fisher's exact test was used for categorical comparisons. Independent-samples t-test or Mann–Whitney U test was used for continuous variables where appropriate. A p value <0.05 was considered statistically significant.

A total of 60 patients with orbital complications secondary to rhinosinusitis were included. The mean age was 29.6 ± 17.4 years. Thirty-eight (63.3%) patients were male and 22 (36.7%) were female.

Table 1. Demographic and clinical characteristics

Eyelid edema was the most common orbital manifestation, occurring in 93.3% of patients. Proptosis and restricted ocular movements were predominantly observed in patients with postseptal complications.

Table 2. Pattern of paranasal sinus involvement

*Multiple sinuses could be involved in the same patient.

Ethmoid sinus involvement was the most frequent radiological finding. Combined ethmoid and maxillary disease was common, while sphenoid sinus involvement was comparatively uncommon.

Table 3. Distribution according to Chandler classification

Preseptal cellulitis represented the largest group, followed by orbital cellulitis. Approximately one-third of patients had abscess formation or cavernous sinus involvement.

Table 4. Management according to severity

Medical management alone was sufficient for most Stage I and a substantial proportion of Stage II patients. In contrast, almost all patients with subperiosteal abscess and all patients with orbital abscess in this illustrative dataset required surgical management.

Table 5. Clinical outcomes

Overall clinical outcome was favorable. Fifty-five patients achieved complete recovery without significant residual visual deficit. Persistent morbidity occurred primarily among patients presenting with advanced postseptal disease.

Orbital involvement remains an important complication of rhinosinusitis because of its potential for rapid progression and permanent visual morbidity. Although contemporary antimicrobial therapy, CT/MRI imaging and endoscopic surgery have substantially improved management, complicated bacterial rhinosinusitis continues to occur.1 EPOS 2020 identifies orbital complications as the most frequent major complications of acute bacterial rhinosinusitis, accounting for approximately 60–80% of complicated cases.1 In the present illustrative series, males constituted 63.3% of patients. Several published series have similarly reported male predominance among patients developing complicated rhinosinusitis.1 Differences in age distribution, referral patterns and the relative contribution of pediatric and adult patients may influence demographic findings across studies. Acute rhinosinusitis accounted for 70% of cases, while chronic rhinosinusitis accounted for 30%. Acute bacterial rhinosinusitis is a well-recognized precipitating condition for orbital complications, particularly among children, whereas chronic rhinosinusitis may play a relatively greater role in complicated disease among adults.1 Ethmoid sinus involvement was found in 81.7% of patients and represented the most frequently involved sinus. This finding is anatomically plausible because the ethmoid labyrinth is separated from the orbit by the thin lamina papyracea. Direct extension through this thin bone, congenital dehiscences, and spread through valveless venous channels facilitate orbital involvement.1,3 Mortimore and Wormald also observed frequent multis sinus involvement in patients with complicated sinusitis.3 The most common complication in this study was preseptal cellulitis (38.3%), followed by orbital cellulitis (28.3%) and subperiosteal abscess (21.7%). Orbital abscess and cavernous sinus thrombosis were relatively uncommon. Published studies show considerable variation in the relative proportions of these complications depending on the population and referral setting.1,5 The Chandler classification remains clinically useful for describing increasing degrees of orbital involvement, although subsequent authors have highlighted anatomical limitations of the original system.2,3 Proptosis, restricted extraocular movements, diplopia, and visual deterioration were particularly important findings suggesting postseptal involvement. Previous work has similarly shown that proptosis and decreased ocular movement correlate with postseptal disease, while visual impairment is particularly concerning in advanced orbital infection.3 These findings emphasize the importance of serial assessment of visual acuity, pupillary responses, color vision and ocular movements rather than relying solely on eyelid appearance. Contrast-enhanced CT is central to evaluating suspected postseptal complications because it demonstrates the extent of sinus disease and can identify orbital cellulitis, subperiosteal collections and intraorbital abscesses. MRI has an additional role where intracranial extension or cavernous sinus involvement is suspected.1 In this study, 56.7% of patients were treated medically, while 43.3% required surgery. The need for surgery increased markedly with disease severity. EPOS guidance indicates that evidence of an abscess on CT, progressive orbital findings, visual deterioration, or failure to improve after initial intravenous antimicrobial treatment should prompt consideration of surgical exploration and drainage.1 Nevertheless, selected pediatric subperiosteal abscesses may sometimes be managed conservatively under strict clinical and radiological monitoring.1,6 Complete recovery without significant visual impairment occurred in 91.7% of patients in the illustrative dataset. The favorable outcome emphasizes the value of early diagnosis, imaging, intravenous antimicrobial therapy and timely surgical intervention. Conversely, advanced disease at presentation may increase the risk of residual visual dysfunction. The management of orbital complications therefore requires close collaboration between ENT surgeons, ophthalmologists, radiologists and, where intracranial disease occurs, neurosurgical and infectious-disease teams. Repeated objective ophthalmological examination remains essential because clinical deterioration may necessitate urgent modification of treatment.

Orbital complications represent serious, potentially vision-threatening manifestations of acute and chronic rhinosinusitis. Ethmoid sinus involvement is particularly common because of its close anatomical relationship with the orbit. Eyelid edema is a frequent presenting manifestation, while proptosis, ophthalmoplegia, diplopia and deterioration of visual acuity should raise concern for postseptal disease. Early clinical recognition, contrast-enhanced imaging, intravenous antimicrobial treatment and repeated ophthalmological assessment are fundamental to management. Patients with uncomplicated disease may respond to conservative therapy, whereas abscess formation, progressive orbital findings, visual deterioration, or inadequate response to appropriate medical treatment may necessitate prompt surgical intervention. A multidisciplinary approach involving otorhinolaryngology and ophthalmology, supported by radiology and other specialties where required, is important for achieving favorable outcomes and minimizing permanent visual morbidity.

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